[Bug rtl-optimization/114492] [14/15 Regression] Invalid use of gcc_assert (notably in gcc/config/aarch64/aarch64-ldp-fusion.cc)

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114492

--- Comment #7 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Alex Coplan <acoplan@gcc.gnu.org>:

https://gcc.gnu.org/g:d6d7da92fb598c50d25332011bffe6b6515c9669

commit r15-7854-gd6d7da92fb598c50d25332011bffe6b6515c9669
Author: Alex Coplan <alex.coplan@arm.com>
Date:   Wed Mar 5 15:45:09 2025 +0000

    pair-fusion: Add singleton move_range asserts [PR114492]

    The PR claims that pair-fusion has invalid uses of gcc_assert (such that
    the pass will misbehave with --disable-checking).  As noted in the
    comments, in the case of the calls to restrict_movement, the only way we
    can possibly depend on the side effects is if we call it with a
    non-singleton move range.  However, the intent is that we always have a
    singleton move range here, and thus we do not rely on the side effects.

    This patch therefore adds asserts to check for a singleton move range
    before calling restrict_movement, thus clarifying the intent and
    hopefully dispelling any concerns that having the calls wrapped in
    asserts is problematic here.

    gcc/ChangeLog:

            PR rtl-optimization/114492
            * pair-fusion.cc (pair_fusion_bb_info::fuse_pair): Check for
singleton
            move range before calling restrict_movement.
            (pair_fusion::try_promote_writeback): Likewise.